The invention relates to communication systems and in particular to a new and useful method for optical communication of information.
The principle of one-laser heterodyne reception is known from optical measurement techniques.
In several publications, e.g. in "Electronics Letters" vol. 16 (1980) p. 630-631 or in "IEEE Journ. of Quantum Electronics" vol. 22 (1986) p. 2070-2074, this measurement principle is described. The objects are always to measure the spectral power density of the laser phase noise. The known measuring system is always installed at one place, e.g. in a laboratory.
Therefore, it is not suitable for communications of modulated optical signals between two positions spatially separated from each other.